The high-tech, high-price systems are supposed to help inattentive drivers stay in their own lanes, not stray disastrously into nearby cars. But vehicles with the systems showed increased, not decreased, crashes in a study being released today by the Insurance Institute for Highway Safety, a research group for insurers.

The unexpected finding that lane-departure setups increased crashes as much as 10% is inexplicable, IIHS says.

David Zuby, chief research officer at IIHS, speculates that users might find the warning sounds or vibration alerts used by lane departure systems annoying and shut them off. Or the alarms are too frequent as drivers stray slightly side to side in normal diving, and so are ignored.

That, of course, explains why they might do no good, but not necessarily why they’d do harm, he acknowledges.

The result also could be a statistical quirk, because few cars in the study had the safety feature.

This is just one study so we shouldn’t be alarmed. These things take time for drivers to figure out, but it also highlights the fact that in some ways cars are becoming too complicated to operate properly for some people.